From fc7fba878bb8442d3751ff556d50436deea9c680 Mon Sep 17 00:00:00 2001
From: Ole Tange <ole@tange.dk>
Date: Mon, 17 May 2010 08:41:28 +0200
Subject: [PATCH] src/parallel: Number of remote CPUs now detected. Potential
 bug: If max_command_length is different on the machines.

---
 src/parallel | 78 +++++++++++++++++++++++++++++-----------------------
 1 file changed, 44 insertions(+), 34 deletions(-)

diff --git a/src/parallel b/src/parallel
index b2b3d473..e7308db6 100755
--- a/src/parallel
+++ b/src/parallel
@@ -267,12 +267,21 @@ Print the number of CPUs and exit (used by GNU B<parallel> itself to
 determine the number of CPUs on remote machines).
 
 
-=item B<--number-of-cores>
+=item B<--number-of-cores> (not implemented)
 
 Print the number of cores and exit (used by GNU B<parallel> itself to determine the
 number of cores on remote machines).
 
 
+=item B<--interactive>
+
+=item B<-p>
+
+Prompt the user about whether to run each command line and read a line
+from the terminal.  Only run the command line if the response starts
+with 'y' or 'Y'.  Implies B<-t>.
+
+
 =item B<--quote>
 
 =item B<-q>
@@ -283,15 +292,6 @@ QUOTING. Most people will never need this.  Quoting is disabled by
 default.
 
 
-=item B<--interactive>
-
-=item B<-p>
-
-Prompt the user about whether to run each command line and read a line
-from the terminal.  Only run the command line if the response starts
-with 'y' or 'Y'.  Implies B<-t>.
-
-
 =item B<--no-run-if-empty>
 
 =item B<-r>
@@ -1261,7 +1261,7 @@ sub parse_options {
     if(defined $::opt_P) { 
 	for my $sshlogin (keys %Global::host) {
 	    $Global::host{$sshlogin}{'max_no_of_running'} =
-		compute_number_of_processes($::opt_P);
+		compute_number_of_processes($::opt_P,$sshlogin);
 	}
     } else {
 	for my $sshlogin (keys %Global::host) {
@@ -1491,9 +1491,10 @@ sub is_acceptable_command_line_length {
 sub compute_number_of_processes {
     # Number of processes wanted and limited by system ressources
     my $opt_P = shift;
-    my $wanted_processes = user_requested_processes($opt_P);
+    my $sshlogin = shift;
+    my $wanted_processes = user_requested_processes($opt_P,$sshlogin);
     debug("Wanted procs: $wanted_processes\n");
-    my $system_limit = processes_available_by_system_limit($wanted_processes);
+    my $system_limit = processes_available_by_system_limit($wanted_processes,$sshlogin);
     debug("Limited to procs: $system_limit\n");
     return $system_limit;
 }
@@ -1504,6 +1505,7 @@ sub processes_available_by_system_limit {
     # Limits are: File handles, number of input lines, processes,
     # and taking > 1 second to spawn 10 extra processes
     my $wanted_processes = shift;
+    my $sshlogin = shift;
     my $system_limit=0;
     my @command_lines=();
     my $next_command_line;
@@ -1609,19 +1611,20 @@ sub enough_file_handles {
 sub user_requested_processes {
     # Parse the number of processes that the user asked for
     my $opt_P = shift;
+    my $sshlogin = shift;
     my $processes;
     if(defined $opt_P) {
 	if($opt_P =~ /^\+(\d+)$/) {
 	    # E.g. -P +2
 	    my $j = $1;
-	    $processes = $j + no_of_cpus();
+	    $processes = $j + no_of_cpus_sshlogin($sshlogin);
 	} elsif ($opt_P =~ /^-(\d+)$/) {
 	    # E.g. -P -2
 	    my $j = $1;
-	    $processes = no_of_cpus() - $j;
+	    $processes = no_of_cpus_sshlogin($sshlogin) - $j;
 	} elsif ($opt_P =~ /^(\d+)\%$/) {
 	    my $j = $1;
-	    $processes = no_of_cpus() * $j / 100;
+	    $processes = no_of_cpus_sshlogin($sshlogin) * $j / 100;
 	} elsif ($opt_P =~ /^(\d+)$/) {
 	    $processes = $1;
 	    if($processes == 0) {
@@ -1643,6 +1646,21 @@ sub no_of_cores {
     return no_of_cpus(@_);
 }
 
+sub no_of_cpus_sshlogin {
+    # Number of CPUs at this sshlogin
+    my $sshlogin = shift;
+    if(not $Global::host{$sshlogin}{'ncpus'}) {
+	if($sshlogin eq ":") {
+	    $Global::host{$sshlogin}{'ncpus'} = no_of_cpus();
+	} else {
+	    my $ncpu = qx(echo|ssh $sshlogin parallel --number-of-cpus);
+	    chomp($ncpu);
+	    $Global::host{$sshlogin}{'ncpus'} = $ncpu;
+	}
+    }
+    return $Global::host{$sshlogin}{'ncpus'};
+}
+
 sub no_of_cpus {
     if(not $Global::no_of_cpus) {
 	local $/="\n"; # If delimiter is set, then $/ will be wrong
@@ -1819,7 +1837,6 @@ sub start_another_job {
 	}
     } else {
 	# No more file handles
-	warn("Not enough file handles to start another job");
 	return 0;
     }
 }
@@ -1951,26 +1968,19 @@ sub read_sshloginfile {
 
 
 sub parse_sshlogin {
-    my ($ncpu,@login);
+    my (@login);
     if(not @Global::sshlogin) { @Global::sshlogin = (":"); }
-    for my $ssh (@Global::sshlogin) {
+    for my $sshlogin (@Global::sshlogin) {
 	# Split up -S sshlogin,sshlogin
-	push (@login, (split /,/, $ssh));
+	push (@login, (split /,/, $sshlogin));
     }
-    for my $ssh (@login) {
-	if($ssh =~ s:^(\d+)/::) {
-	    $ncpu = $1;
-	} else {
-	    if($ssh eq ":") {
-		$ncpu = no_of_cpus();
-	    } else {
-		$ncpu = qx(echo|ssh $ssh parallel --number-of-cpus);
-		chomp($ncpu);
-	    }
-	}
-	$Global::host{$ssh}{'no_of_running'} = 0;
-	$Global::host{$ssh}{'ncpus'} = $ncpu;
-	$Global::host{$ssh}{'maxlength'} = max_length_of_command_line();
+    for my $sshlogin (@login) {
+	if($sshlogin =~ s:^(\d+)/::) {
+	    # Override default autodetected ncpus
+	    $Global::host{$sshlogin}{'ncpus'} = $1;
+	} 
+	$Global::host{$sshlogin}{'no_of_running'} = 0;
+	$Global::host{$sshlogin}{'maxlength'} = max_length_of_command_line();
     }
     debug("sshlogin: ", my_dump(%Global::host));
 }